1. Field of the Invention
The present invention relates to substrate processing apparatuses and substrate processing methods for applying processing to substrates.
2. Description of the Background Art
A substrate processing apparatus is used to apply a variety of processings to substrates such as semiconductor substrates, substrates for use in liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, photomasks, and other substrates.
Such a substrate processing apparatus typically applies a plurality of successive processings to a single substrate. The substrate processing apparatus described in JP 2003-324139 A comprises an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-described substrate processing apparatus, a substrate is carried from the indexer block into the anti-reflection film processing block and the resist film processing block, where the formation of an anti-reflection film and resist film coating processing are applied to the substrate. The substrate is then carried to the exposure device through the interface block. After exposure processing has been applied to the resist film on the substrate by the exposure device, the substrate is transported to the development processing block through the interface block. In the development processing block, development processing is applied to the resist film on the substrate to form a resist pattern thereon, and the substrate is subsequently carried into the indexer block.
In this substrate processing apparatus, a single holding arm of an interface transport mechanism transports the substrate from the interface block to the exposure device and from the exposure device to the interface block.
With recent improvements in the density and integration of devices, making finer resist patterns have become very important. Conventional exposure devices typically perform exposure processing by providing reduction projection of a reticle pattern on a substrate through a projection lens. With such conventional exposure devices, however, the line width of an exposure pattern is determined by the wavelength of the light source of an exposure device, thus making it impossible to make a resist pattern finer than that.
For this reason, a liquid immersion method is suggested as a projection exposure method allowing for finer exposure patterns (refer to, e.g., WO99/49504 pamphlet). In the projection exposure device according to the WO99/49504 pamphlet, a liquid is filled between a projection optical system and a substrate, resulting in a shorter wavelength of exposure light on a surface of the substrate. This allows for a finer exposure pattern.
However, in the above-described projection exposure device, exposure processing is performed with the substrate and the liquid being in contact with each other. Accordingly, the substrate to which the liquid is attached is transported out of the projection exposure device.
Thus, when combining the substrate processing apparatus according to the aforementioned JP 2003-324139 A with the projection exposure device according to the aforementioned WO99/49504 pamphlet as an external device, the liquid attached to the substrate that is carried out of the projection exposure device settles on the holding arm. Since the holding arm also transports a substrate before exposure processing to the projection exposure device, the liquid settled on the holding arm attaches also to the back surface of the substrate before exposure processing.
Therefore, during the transport of the substrate to the projection exposure device, particles and the like in the atmosphere attach to the liquid on the back surface of the substrate, and contaminate the back surface of the substrate. This may result in degraded resolution performance during the exposure processing due to the contamination of the back surface of the substrate.